Electrolytic condenser



June 12, 1928. 1,673,434

E. F. ANDREWS ELEGTROLYTIC CONDENSER Filed NOV. 7, 1927 @PMLADLGJI Patented June 12,192a

f UNITED-STATES PATENT oFFice.

,EDWARD-F. ANDREWS, OF CHICAGO, ILLINOIS, ASSIGNOB TO AN DBEWS-HAHIOND COB- PORATION, OF- CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Ennozrnonvrrc. coNimNsEa.

Application tiled November 7,1927. Serial No. 231,437.

My invention relates to an; electrolytic condenser, of the same general type as that disclosed in my prior application 101,347,

f filed April.12, 1926, which makes possible 5 enormously greater capapitythan previous typesof condenser, of similar dimensions, particularly at relatively-low voltages., One

^ objectvof my invention is to provide an electrolytic cell adapted to function as a con- 1Q denser incirciiits carrying pulsating, alterf nating or surging currents, which shall have a relatively high capacity, particularly at low voltage'sand which shall be capable of 15 long periods of use or disuse With'very little vision of an electrolytic condenser, one or more of which may be used in connection with one or more ind'uctances, in circuits carrying alternating'V or lpulsating current, to reduce the` alternating component to a minimum, `thus producing a substantially steadydirect current. v

A further object is the provision of a materialfor the plates of an electrolytic condenserof this general type which shall be more durable than lates of pure iron or pure nickel and which can function satisfactorily both as positive and as negative capacity effect at practical operating-voltages.` A further objectof -this invention 1s to provide a material Whichv shall be more economical and which shall lend itself better to quantity production than the nickel plated steel-previously used'and at the same time shall compare favorably tonthis latter materialin point of capacity per unit of area, andwhichshall be superior in durability.'` A furtherobject is the provision of an elec- 40 trolytic condenser which 'shall be' easy and cheap to manufacture and economical to use.

Other objects will appear from tinieto time in the course of the specification and claims/ I illustrate my invention more or less diagrammatically in theaccompanying draw. ings, wherein- Figure l is a cross-section of one of my electro-chemical condensers;

Figure 2 is a plan View of the condenser shown in Fi re l; l

Figure 3 illustrates one of my electrochemical condensers connected across a circuit carrying pulsating current; and

deteriora-tion.. AA further object is-the p ro-v plate, at'the same time maintaining a high Figure 4 illustrates a variant and on the whole preferred type of condenser. f

Like partsare indicated by like symbols throughout the specification and drawings.

ures 1 and 2 illustra-ted as single and are i provided'with the terminals B4 B,1B5 B5, which should be formed to permit of an extremely lowl resistance connection between the-circuit and the condenser. I illustrate the binding posts as B8 and B7.

. C indicates an electrolyte which is preferably of an alkali metal hydroxide, potassium hydroxide being be'st except as to cost. Sodium hydroxide is cheaper. Chlorine should be avoided as an impurity. It may consist ofan aqueous solution of potassium hydroxide. Other electrolytes may be usable. C1 indicates a thin film of oil floating Ion the surface of the electrolyte C, which serves to prevent the electrolyte from absorbing car# bon dioxide from the air, and also retards evaporation. If the container A is provided with a closed top as is preferable in commercial applications of my device, the oil film O1 may generally be omitted.

'I prefer to employ for both positive and negative electrodes a nickel iron or nickel steel alloy. A wide range of roportions of nickel and iron are usable. lilany satisfactory alloys are found in the range up to 18 per cent'nickel. One quite desirable range duce the internal resistance of the cell, and

at the same time to provide'accommodation for plates of suitable area. The capacity` electrodes for the cells they bound andas and smoothing e'ect increases with the plate y area. The thinnessfof the electrodesls lim; ited by the necessity of having them thick enough to `bestrong and durable, and -in the case of those to which connectionsvarev made, they must be. thicki enough to provide ampleconductivity. For largcrcapae cities a plurality of electrodes can beconnected in parallel in the same cell.

` Referring now` to Figure 4 I illustrate a variant form of condenser Which is thought to be preferable for certain commercial uses.

This general type of cell is -that described, shown and claimed in the c'o-pendingapph-l cation 153,488, of Laurens Hammond, liled on December 9, 1926'. E indicates a con-l connecting means for the termin/al plates tainer thc'inner faces of thesides of which y are slotted in parallel as at El to receive the metallic sheets 4which serve a thasame time as partitions between adjace t cells, as

conductors connecting the adjacent 4electrodes. Thus, save for .the terminal plates E3 and E4, each plate serves as the positive electrode for one cell andthe negative electrode forI the adjacent cell. E? E7 in' dicate-binding posts or anyother suitable E3 and EQ.

Referring now to Figure 3 'F indicates a source of alternating current and F1 a transformer for securing the desired voltage. F2 is a rectiierfadapted to permlt the passage of currentv through itin one direction only,

thereby causing a pulsating direct current to `flow in thesccondary coil F3 of thetrans-v 'former F1. Elo generally'indicates an elec-A trolytic condenser, for exam le such. as

shown in Figures 1, 2 or 3, and erein shown as 'consisting of the four cells A2,'A2A and A5, connected across the output vof the secondary coil F8 and the rectiienFz.

G indicatesa choke coilhaving a high re' actance by comparison to its resistance, connected in series with the load diagrammatr cally illustrated as G1. VThe terminals B4 B should -be connected respectively to the l Wires H and H10 leading to the rectifier F2 and the .choke coil respectively. The: opposite terminals B5 B? should beconnected respectively to the Wires Hgand H12 connect.

` ing with the secondary coil F3'. and the load G1 respectively, the load and the ,choke coilthe 'rectifier F2.an`d .the coil 'nectedqgy the wire Ha.

the'line H? in the circuit y shown in Fi ure 3, and

Fa ing conbeing connected by as diagrammatica 1 It will be realized thatfwhereas I have illustrated. andq described a practical and and circuit may be widely varied Withoutsde# partmg from the spirit and intention of my 'for other purposes. Furthermore both cell invention. I-'wish'my drawings anddescription therefore to be'takenas in abroad sense illustrative an diagrammatic ratherthan as limiting. me to my precise showing.

The use and operation -of my'invention areas follows:

My electro-chemical condenser has icharacteristics which radically differentiate it both from condensers and from batteries.

electrolytic condensers in the past have in-A v cluded positive, plates, generali of metal, upon whose surface )vas forme a layer or B0 Afilm of al, relatively' non-'conducting oxide or' hydroxide which served to insulate the conducting surface of the electrode from theelectrplyte. Thisnflmwiscapable of withstanding voltages veryi'nu'ch in excess of the vsolution pressure voltages of the electrodes in conjunction with the specific elec# .trolyte. A' basically novel-feature of my condenser as disclosed herein and in the co-- pending lz'ipplication 101,347, above mente y tioned, is the employment, `asl a positive electrode 1n an electrolyticl condenser, .of a metallic surface which does not become .covered with a non-conducting oxide film and in which the breaksdown voltage is not greatly in excess ofthe solution pressure of theelectrode against the solution.

I may employ a cell having positive and .A

negative electrodes of a nickel iron alloy. One suggested range '-is an alloyhaving up to IZpcr cent 'nickel and I ind'that a range of from 8' lto 12 per cent nickel -is particu-` larlA advantageous.' I do not Wish to be' limited, however, tof-these specilic ranges.v

I find it advantageous for several reasons .to employ a-positive-electrode ora positive.

' and4 a negative electrode in my electrochemicalI condenser consisting of 'an alloy ofv iron and nickel. v'Il 'have experimented with a wide range of proportions of iron to nickel, and believe'that. the'fwhol'e alloy ile series is at least to some extent effectiveforf this purpose. However those alloys con-v 'taining Ia -relatively small percentage of nickel are advantageous on account of their` relatively low.

rice and.have been found toV be very suita le 'for this-purpose. The 'range of alloys having up to 18 percent of nickel are relatively cheap and usable, The range ofl alloys containing from 8 to 12 per cent -of nickel is particularlyadvantageous.` v

I do not wish to be limited however to these specific ranges.

to roll vand. -which shall have desirable It isdesirable of course to vselect analloy which shall be fairly easy.

mechanicalproperties such as ductility comnbinedwith reasonable strength. Certain o'f the alloys in the range up to 18fper cent of nickel are" not well adapted to' rolling into. sheets The range from to 12 per cent is as a positive Aplate to a much greater extent ten however, good from this point of lview and tric current is being passed through `the 'sheet itsq'mechanicall properties are satisfactory. which y*forms one or more of the electrodes An alloy containing ten per cent of'nickel in the etching cel-l, The etchingq of iron and the balance iron including certain minor nickel alloy electrodes apparently increase impurities has been found quite satisfactory their capacitative etl'ect. 'lhe roll stockl from all ints of view. The durability oli-supplied from the rolling mills is of a dark. iron nicke alloy both as a positive and negagray color with'a considerable scale. When tive plate in the solution of an alkali metal etched as above described in 7 per cent sulhydroxide is extremely good.- As a positive phuric acid the scale is removed and the plate it is very much better than iron. vAs' vmetal comes out quite white looking, much a negative plate it is Very much better than like pure nickel. It should be of course either nickel or iron. Iron tends to oxidizel Washed thoroughly to remove all acid. The per cent nickel alloy has a relatively than the iron nickel alloy, While nickel as a smal tendency to rust. negative plate under certain conditions of -I claim: pulsating current disintegrates quite rapidly. 1. Inv an electrolytic condenser adapted The iron nickel alloy remains clean and .for use in electric circuits carrying alternatbright for great lengths of time both as a Iing' or pulsating currents, which includes positive and negative electrode and under electrodes and an electrolyte, a metallic posi- Very 'diilicult conditions of service. The tive electrode formed of an alloy of nickel iron nickel alloy when employed for both and iron. positive and negative plat' of my con- 2. In an eleetrolytic condenser adapted denser gives almost if not fully fas, high a for-use in electric circuits carrying alternatcapacity per unit of area as that obtainable .ing or pulsating currents, which -includes when a positive of ,pure nickel and a nega-4 electrodes and -an electrolyte, metallic positive of pure iron is employed. There is a tive and negative electrodes formed of a great advantage in having both positive and nickel iron alloy. negative plates composed'of the same ma- 3. In an electrolytic condenser 4adapted terial. In the .first place the polarity of the for use'in electric circuits carrying altercondenser is Qreverslble under these condi-v nating or pulsating currents, Whichincludes tions without changing the capacity of the electrodes and an electrolyte, a posit-ive condenser while if an iron negative and a electrode having an effective metallic surnickel positive is employed if the clarity face of ,a' nickel iron alloy. j

is changed so that the iron-becomes t e posi- 4. In an electrolytic condenser adapted tive and the nickel the negative the capacity for use in electric circuits carrying alternat- 100 effect will be very greatly reduced. The lngor pulsating currents, which includes elecuse of the same material for both plates is trodes and an electrolyte, a metallic ositive also particularly advantageous where the leCtIQde OImd 0f .an allOy 0fv Ilic -el and plate is employed as a, bi. 01er electrode es` lron, including 17 per cent /or less'of nickel.

is shown inthe Figure 4 o the drawing. If

uol

- plates 0f different materiels -are used here usein electriccircuits carrying alternating or -do not noticeably disintegrateas a result of ii; is. necessary to plate one material upon pulsating currents, which includes electrodes the otheror to otherwisevform al composite and ,an eleCtIOl e,' a metallic positive elecsheet, the positive -face of which is nickel trode formed o an alloy of nickel and iron, and the negative face 0f which is iron, If including from 8 to 12 percent of nickel.

one metal is plated on to the-"other it `is 6. In an elcctrolytic condenser adapted very ditiicult to secure a closely adherent vfor use in electric circuits carrying altercoatingr and almost impossible to secure one natin-g or pulsatingv currents, which includes free from pores. In passing, attention Aelectrodes and an electrolyte, metallic posii might be called` t-o the fact that in the use tive and negative electrodes formed of a of my two electrodes of the 'same material nickel iron alloy, including 17 per cent or both remain relatively clean and bright and less of nickel. e

` 7. In x an electrolytic condenser adapted electrolytic action, which brings out clearly for use' in electric circuits carryin alterthe di'ference between my electro-chemical nating or pulsating currents, which includes 120 condenser and a-storage battery. l electrodes and an electrolyte, metallic posi- I n the preparation o f the plates they "arel tive and negative electrodes formed .of a preferably etched'.v The sheets may4 be nickelironalloy, including from 8 to 12 per etched as they are supplied by the rolling centfof nickel. mills. They can .beetched either by i-m- 8. In an electrolytic condenser adapted 125 mersing the Aplate in a 'suitable etching solufor use in electric circuits carrying a tertion such as 7 per cent sulphuric acid,- the hating-or pulsating currentswhich includes bathv being maintained -in^a temperature in electrodes and an e1ectrolyte,'a metallic bithe, vicinity of degrees F., or they can polar electrode formed of an alloy of lnickel be etched in a. similar solution while an elec-. and iron.v

5. In an electrolytic condenser adapted for v105 9.J In anv electrolytic condenser adapted' -for use in electric circuits carrying. alternating or pulsating currents which ing-- `cludes electrodes and an electrol7 cludes electrodes andan electrolyte, a metal-v f lic bi-polar electrode formed oan alloy of nickel and iron, including from 8 to 12 per cent of nickel.- 3

A11. In an electrolytic condenser allapted forv use in electric circuits carrying alter- A nating or pulsating currents, which 1ncludes electrodes and an electrolyte, a metallic bi-polar electrode consisting of a -thin 20 sheet of an alloy of nickel and iron.

.12. In an electrolytic condenser adapted *foruse in electric circuits carrying alternating vor `pulsatingv currents, which includes electrodes and an' electrolyte, a plu-` rality of metallic bi-polar electrodes formed- `of an alloy of nickel and iron. y 13. In an electrolytic condenser adapted for 'use in electriccircuits carrying alterjnating or pulsating currents, Whichincludes'electrodesv andan electrolyte,a plurality of metallic bi-polar electrodes formed of an alloy of nickel and iron, acontainer for said electrodes`andua separate body -of electrolyte between each pair ofsaid elec- 'I' State of'Ill1no1s,-.this 5th day of November,

,trode's, the electrodesbeing adapted to serve as partitions between the cells so formed.

'14. IIn an yelectrolytic condenser adapted for use in electricv circuits carrying alternating ,or pulsatin currents, which includes electrodes an anelectrolyte, a positive electrode, the effective portion of which consistsof a surface of an alloy of nickel and iron.

15. In an electrolytic condenser adapted for use in electric circuitsv carrying alterhating' orpulsating' currents, which includes electrodes and an electrolyte, a positive electrode, the effective portion of which consists'of a' surface'of analloy 5f nickel l v and iron, and a plurality of 'bi-polar electrodes formed of an alloy of nickel and iron. 16. In an electrolytic condenser adapted for use in electric circuits lcarrying alternating or pulsating currents, which lincludes .electrodes and an electrolyte, a positive elect-rode, the Veffective portion of vwhich yconsists of a surface of an alloy of nickel and iron, acontainer for said electrodes and a separate body of electrolyte between eachpair ofsaid electrodes, the electrodes being adapted`v to` serve aspartitions between the cells so formed. f

17. Inan electrolytic condenser which includes electrodes and an electrolyte, a solid -metallic positive electrode, the essential portion of which includes a nickel ironjalloy.

18. In an electrolytic condenser which includes-electrodes and an electrolyte, a solid metallic bi-polar electrode, the essential portion of which includes a nickel iron alloy. Signed at kghicagdvcounty of Cook and Y EDWARD F. ANDREWS.- 

